K deficiency???

Hi! Some of the leaves starting showing this discoloration. Is this K def?
3 weeks into flowering.
Being fed: BioGrow 1,5mL/L, BioBloom 2mL, TopMax 2mL/ and Hesi SuperVit 1drop/5L.

By the way, if anyone could help me with this also I would appreciate.
Thank you!

Any suggestion?

Can anyone help me sort this out?

I have a similar thing going on with one of mine and I also thought it was K def. I posted on here about it a couple days ago you can see pics of mine and let me know what you think. Anyway, I was told it may be zinc def. Due to a high ph locking out the nute. If your ph is above 6.5 you might want to look into that. Good luck!

Yes, my pH is at 7 now (3 weeks into flowering). When I started flowering it was 7,5. Did the lemon juice work for you? used it to try to bring it down for weeks but not with much success... I mean, it dropped a bit but not as much as necessary.

Could also be magnesium. I had a problem with magnesium when i used the biobizz stuff cause i dont think they contain any magnesium. Try flushing your soil, and get some stuff called "calmag" or if you wanna stick to organics biobizz has stuff called "alg-a-mic" which contains magnesium and calcium. See how that does.

You can also use epsom salts to correct the problem if it is magnesium. The best thing about the treatment for this is you only have to do it twice of three times throughout the whole course of the grow.
Maybe this link will help http://www.uk420.com/boards/lofiversion/index.php/t24031.html

what u growing in?

what is the ph of the water?

what is the strengh showing on your EC/ ppm

Growing in Compo Sana Universal Compact soil (fertilized soil with perlite and agrosil, a root stimulator). It's pH is 5,5-6,5. My water is 6,5. Fed them BioGrow and Hesi SuperVit during veg. The pH rose above 7,5 but I had no problems. Managed to lower it a bit with lemon juice. Now feeding BioBloom, Top Max, BioGrow, Hesi SuperVit. Weekly I give them some foliar feeding but I'll stop it now because I don't wanna risk spraying my buds. Apart from them, I used VitaTerra Algas, a cheap Alg-a-Mic like product I bought... not sure if it really does the job. It contains Mg in it so I think I'll try it today. Cheers!

EDIT: by the way, if someone could help me out with this I'd be really grateful!